drm/i915: Kill GTT mappings when moving from GTT domain
In order to force a page-fault on a GTT mapping after we start using it
from the GPU and so enforce correct CPU/GPU synchronisation, we need to
invalidate the mapping.
Pointed out by Owain G. Ainsworth.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index abe6d90..d4d8f88 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1314,12 +1314,12 @@
ret = i915_gem_object_bind_to_gtt(obj, 0, true);
if (ret)
goto unlock;
-
- ret = i915_gem_object_set_to_gtt_domain(obj, write);
- if (ret)
- goto unlock;
}
+ ret = i915_gem_object_set_to_gtt_domain(obj, write);
+ if (ret)
+ goto unlock;
+
if (!obj_priv->fault_mappable) {
obj_priv->fault_mappable = true;
i915_gem_info_update_mappable(dev_priv, obj, true);
@@ -2859,6 +2859,8 @@
* to it immediately go to main memory as far as we know, so there's
* no chipset flush. It also doesn't land in render cache.
*/
+ i915_gem_release_mmap(obj);
+
old_write_domain = obj->write_domain;
obj->write_domain = 0;
@@ -3183,6 +3185,10 @@
if ((flush_domains | invalidate_domains) & I915_GEM_DOMAIN_CPU)
i915_gem_clflush_object(obj);
+ /* blow away mappings if mapped through GTT */
+ if ((flush_domains | invalidate_domains) & I915_GEM_DOMAIN_GTT)
+ i915_gem_release_mmap(obj);
+
/* The actual obj->write_domain will be updated with
* pending_write_domain after we emit the accumulated flush for all
* of our domain changes in execbuffers (which clears objects'